Anthrocerophyta Anthrocerophyta, one of the smallest phylums in the Plant kingdom which contains only 5 classes, are one of the most unusual plants on planet. Anthrocerophyta consists of only one group of plants known as Hornworts. Hornworts are a group of bryophytes, or non-vascular plants, comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. The flattened, green plant body of a hornwort is the gametophyte plant. Hornworts can be found world-wide, though they tend to grow only in places that are damp or humid. Some species grow in large numbers as tiny weeds in the soil of gardens and cultivated fields. Large tropical and sub-tropical species of Dendroceros may be found growing on the bark of trees. Currently there are five classifications of hornwort, each with it's own number of species ranging from 1 to 83 in total. Hornworts have been grouped as horned liverworts in the subclass Anthocerotidae, the Anthocerotopsida class, the Anthocerotales order, or can be entirely separated from the bryophytes in the Anthocerotophyta division. Anthoderos have a worldeide distrabution. Dendroceros and Megaceros are a tropical genra. Hornworts usually grow on damp soils or rocks in tropical and warm temperate regions. The plants gametophytes are typically flattened, irregularly lobulated structures that are usually less tha 2 cm in diameter. The sporophyte, forms a tapered cylinder and it is dependant on the gametophyte for nutrients and water and grow to be 5 cm. The thallus usually lacks a midrib, the sexual organs are sunk into the upper surface of the thallus.
Hornwort Bio Because hornworts are non-vascular they lack a xylem and phloem (two types of vascular tissue), so that means that they are also neither monocots or dicots. This is consistent with the fact that hornworts are a type of moss, which is why they are classified as bryophytes. Depending on the species hornworts can be either bisexual or unisexual, and the sex organs may be distributed on the surface. Hornworts reproduce by means of water-borne sperm which travel from the antheridium to the archegonium. A fertilized egg from a female develops into an elongated sporangium, which splits lengthwise as it grows releasing spores that have developed with in it.
Facts About Anthrocerophyta
"The sporophyte is parasitic (dependent!) on the gametophyte."
"In hornworts, as for all other bryophytes, the dominant phase of the life cycle is the gametophyte (haploid)."
"The plant is called a thallus."
"Spores are usually shed by wind."
Citation: "Plant Reproductive System :: Bryophyte Reproductive Systems -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 25 May 2011. "Hornwort (liverwort) -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 25 May 2011. "Bryophytes: Hornworts." Home Page for Ross Koning. Web. 25 May 2011. "Hornwort: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web. "Bryophytes: Hornworts." Fachbereich Biologie - UNI HH. Web. 25 May 2011.
Anthrocerophyta, one of the smallest phylums in the Plant kingdom which contains only 5 classes, are one of the most unusual plants on planet. Anthrocerophyta consists of only one group of plants known as Hornworts. Hornworts are a group of bryophytes, or non-vascular plants, comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. The flattened, green plant body of a hornwort is the gametophyte plant. Hornworts can be found world-wide, though they tend to grow only in places that are damp or humid. Some species grow in large numbers as tiny weeds in the soil of gardens and cultivated fields. Large tropical and sub-tropical species of Dendroceros may be found growing on the bark of trees. Currently there are five classifications of hornwort, each with it's own number of species ranging from 1 to 83 in total. Hornworts have been grouped as horned liverworts in the subclass Anthocerotidae, the Anthocerotopsida class, the Anthocerotales order, or can be entirely separated from the bryophytes in the Anthocerotophyta division. Anthoderos have a worldeide distrabution. Dendroceros and Megaceros are a tropical genra. Hornworts usually grow on damp soils or rocks in tropical and warm temperate regions. The plants gametophytes are typically flattened, irregularly lobulated structures that are usually less tha 2 cm in diameter. The sporophyte, forms a tapered cylinder and it is dependant on the gametophyte for nutrients and water and grow to be 5 cm. The thallus usually lacks a midrib, the sexual organs are sunk into the upper surface of the thallus.
Hornwort BioBecause hornworts are non-vascular they lack a xylem and phloem (two types of vascular tissue), so that means that they are also neither monocots or dicots. This is consistent with the fact that hornworts are a type of moss, which is why they are classified as bryophytes. Depending on the species hornworts can be either bisexual or unisexual, and the sex organs may be distributed on the surface. Hornworts reproduce by means of water-borne sperm which travel from the antheridium to the archegonium. A fertilized egg from a female develops into an elongated sporangium, which splits lengthwise as it grows releasing spores that have developed with in it.
Citation:
"Plant Reproductive System :: Bryophyte Reproductive Systems -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 25 May 2011.
"Hornwort (liverwort) -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 25 May 2011.
"Bryophytes: Hornworts." Home Page for Ross Koning. Web. 25 May 2011.
"Hornwort: Facts, Discussion Forum, and Encyclopedia Article." AbsoluteAstronomy.com. Web.
"Bryophytes: Hornworts." Fachbereich Biologie - UNI HH. Web. 25 May 2011.
External Links:
http://www.britannica.com/facts/5/606647/hornwort-as-discussed-in-plant-reproductive-system
http://www.britannica.com/EBchecked/topic/272087/hornwort
http://plantphys.info/plant_biology/hornwort.shtml
http://www.absoluteastronomy.com/topics/Hornwort
http://www.biologie.uni-hamburg.de/b-online/library/plant_biology/hornwort.html
http://www.biologie.uni-hamburg.de/b-online/library/plant_biology/hornwort.html